-Heat the oven to 425°F and arrange a rack in the middle.
-Line a baking sheet with aluminum foil. Place the squash pieces cut-side up on the baking sheet. Spray with cooking spray (or spread olive oil on the squash). Roast until knife tender, about 50 minutes to 1 hour.
-Melt the remaining tablespoon of butter in a large soup pan or Dutch oven over medium heat. Add the apple, onion, and sage, season with salt and pepper, and cook, stirring occasionally, until softened, about 7 minutes. Remove the pan from the heat and set aside.
-When the squash is ready, set the baking sheet on a wire rack until the squash is cool enough to handle. Using a large spoon, scoop the flesh into the pan with the sautéed apples and onions; discard the skins.
-Add the broth, stir to combine, and bring to a boil over medium-high heat. Reduce the heat to medium low and simmer, stirring occasionally and breaking up any large pieces of squash for about 15 minutes. Remove the pan from the heat and stir in the cream.
-Using an immersion blender, purée the soup until smooth.
-Taste and season with salt and pepper as needed. IF too thick, add some water to desired consistency.